1. Field of the Invention
The present invention relates to an elastic rubber bearing with integrated hydraulic damping or cushioning, in which a bearing core, a ring-shaped spring element, and a bottom plate enclose a work chamber which is filled with a hydraulic fluid. The work chamber communicates through a restrictive or throttled opening with a liquid-filled expansion chamber which is changeable in volume, and wherein intermediate the two chambers there is positioned a separating wall constituted of an elastic material and a rigid separating wall having perforations therein.
2. Discussion of the Prior Art
From the disclosure of German Pat. No. 32 25 700 there has become known an elastic rubber bearing, or socalled silent block bearing, in which a bearing core, a ring-shaped or annular spring element, and a bottom plate enclose a work chamber which is filled with a hydraulic fluid or liquid. The work chamber is separated from a liquid-filled volumetrically-variable expansion chamber through the interposition of a separating wall of an elastic material which is provided with slits, and with rigid separated walls being arranged on both sides of the latter which possess perforations. An annular passageway is provided in the separating walls. During the initiation of vibrations, the pressure which acts on the separating walls will fluctuate. An opposition to an increase in pressure is caused by the increasing passage of fluid through the restricted opening, which attains its optimum upon reaching of the limiting pressure. At the occurrence of a pressure drop-off, this is compensated for by a cut which then opens into a slit. The throttling or restrictive cross-section is thus imparted a constant expansion in dependence upon the pressure differential which is available between the working chamber and the expansion chamber, such that, especially at vibrations having a high amplitude and low frequency, there is added a hydraulic damping to the damping of the material.
Herein, it is disadvantageous that within the supercritical range, vibrations possessing a high frequency and low amplitudes are only sufficiently acoustically isolated, inasmuch as the heretofore known bearings will dynamically stiffen themselves extensively at an increase in the frequency.